Fire control apparatus



Aug. 15, 1944. H. M MANN FIRE CONTROL APPARATUS Filed Aug. 16, 1940 2Sheets-Sheet 1 J E 4 32 g a 3 33 INVENTOR 9 IRA H.MMAN F162. 4

MTATTORNEYS Aug. 15, 1944. I. H. MCMANN 2,355,664

FIRE CONTROL APPARATUS Filed Aug. 16, 1940 2 Sheets-Sheet 2 INVENTORIRAH.MMA

ATTORNEYS Patented Aug. 15, 1944 tearcn HOOm UNITED STATES PATENT OFFICE9 Claims.

This invention relates, generally, to fire detecting and arrestingapparatus, and particularly to such apparatus as is adapted to detectand arrest fires in ducts through which inflammable material istransmitted in air suspension.

In many industries, such for example as the textile industry, finelydivided inflammable materials are transmitted from point to point in astream of air, through suitably arranged ducts. For example, in thetextile industry, particles of the textile materialfm or rayon, aretransmitted, at certain stages of the operations, by a stream of airthrough suitably arranged ducts. Such ducts may originate in one room orbuilding, and extend to another room or building, into the latter ofwhich the material is delivered. Since a fan or blower is employed inconnection with such means for transporting the inflammable material,sparks not infrequently occur in the fan or blower, due either tomechanical defects or the presence of foreign substances; and in suchcases the inflammable material in the stream of air is ignited, with theresult that the flame is immediately transmitted to the room or buildingat the delivery end of the duct.

An object of the present invention, generally stated, is to provide anapparatus for'detecting the presence of flame in ducts for transmittinginflammable material, and for setting in motion suitable apparatus forarresting the fire.

A further object of the invention is to provide a fire detectingorganization so constructed and arranged as to detect incipient fires inrapidly moving streams of inflammable material.

Other objects will become apparent to those skilled in the art when thefollowing description is read in connection with the accompanyingdrawings, in which:

Figure 1 is a diagrammatic view illustrating the application of theapparatus of the present invention in the conventional duct fortransmitting cotton fibres from the opening room to the picker room of acotton mill.

Figure 2 is a wiring diagram of the electrical apparatus employed inconnection with the flre detecting and. arresting apparatus of thepresent invention.

Figure 3 is a detail view of a diverting switch employed in the cottonduct in connection with the embodiment of the present invention, asillustrated in Figure 1.

Figure 4 is a detail view showing arrangement of the fire door in acotton duct, and suitable control apparatus therefor.

Figure 5 is a detail view, showing the arrangement of photo-electriccells in connection with the cotton duct.

In accordance with the present invention, generally stated, the tube orduct through which inflammable materials are transported in a stream ofair or other gas may be provided with a window or series of windows atspaced intervals throughout its length, and so arranged that lightoriginating on the interior of the duct may be detected by aphoto-electric cell or other light detecting means, arranged on theexterior of the duct. In the detection of fires in such ducts as areemployed in cotton mills, however, the incipient stage of the fireexists when one or more, but a limited number, of fibers have becomeignited, and in such condition only a vestige of light is emitted by thefire in this incipient stage. The quantity of light emitted by a flrewhich has progressed no farther than a few particles of inflammablematerial, such as cotton or rayon, is not suflicient to so energize anordinary lphotoelectric cell that the photo-electric cell may bedepended upon to actuate electrical or mechanical means for arrestingthe fire, and consequently, in order to arrest the fire in its incipientstage, the present invention contemplates the provision of amplifyingmeans for amplifying the current delivered by a photo-electric cellwhich detects the presence of flame, to a sum-- cient extent to permitthat current to actuate a relay which, in turn, effects a closure of theduct at or near the delivery end thereof, and interrupts the flow of theair stream conveying the inflammable material.

The present invention further contemplates the provision of meanswhereby the stream of ignited material travelling through the duct isdiverted into a suitable fire-proof chamber, which may be equipped withautomatic sprinklers and other desirable fire control devices forextinguishing the flame, without immediately interrupting the supply ofair to the duct, thereby permitting the fire in the duct to burn itselfout, and thereby avoiding accumulation of ash in the duct, such as wouldresult if the flow of com bustibles were arrested immediately upondetection of the fire. The flow of material through the duct istherefore, desirably continued for a brief period after the stream hasbeen diverted. Diversion, as distinguished from damming the stream,avoids the building up of excessive pressure within the duct.

While the invention will be described with particular reference to theapplication thereof to cotton mills, it is to be distinctly understoodthat the invention is not limited to cotton mills, or even to thetextile industry; but that the features thereof are applicable at largeto many industrial applications of the transportation system wherein astream of inflammable material is transported in air suspension; andsuch reference as is herein made to cotton mills, cotton ducts, andother conventional apparatus employed in the textile industry are by wayof illustration, and not by way of limitation.

Referring now to the drawings for an illustrative embodiment of thepresent invention, the usual opening room of a cotton mill isdiagrammatically shown at I. Provided in the opening room is a hopper 2into which the fibrous cotton is fed. Materials deposited in hopper 2are forced through a chute 3 by an electric motor 4, in a manner wellknown to those skilled in the art, and are discharged upon a conveyor 5which operates in the direction indicated by the arrow. At the oppositeend of the conveyor 5 is a suction tube 6, associated with a suitableblower I, and arranged to suck the cotton fibers from conveyor 5 throughtube 6.

Blower l is driven by an electric motor 8 through a suitably arrangedbelt and pulley combination 9, or otherwise, as desired.

A duct l extends from the delivery end of blower I to another enclosurel l, commonly called the picker room, in a cotton mill; and the materialthus transported through duct I0 is discharged into the picker room I lIn accordance with the present invention, a fire door I2 is providedadjacent the discharge end of duct I0, and arranged to be held normallyopen but by mechanism hereinafter described in detail, the fire door I2is arranged to be closed upon the detection of light in duct Hi.

In the embodiment illustrated in the drawings, provision is made forby-passing the ignited stream of material to a fire proof chamber l3after fir door I2 has become closed. Accordingly, an auxiliary duct l4extends from duct 10, being arranged immediately adjacent fire door ill,but on the blower side thereof, and terminates in fire proof chamber 13.The fire proof chamber l3 may be provided with automatic sprinklers, orwith other fire control devices well known to those skilled in the art.At the juncture between duct l0 and auxiliary duct M, a switch I5 isprovided. The switch [5, when in normal position, closes the mouth ofauxiliary duct H, but is arranged, in connection with the mechanism tobe described in detail hereinafter, to open the mouth of duct l4 uponthe detection of an incipient fire in duct Ill.

In spaced relation lengthwise of duct ID is a series of windows l6, fourof which are shown in the embodiment illustrated in Figure 1, but anynumber of which, preferably more than one, may be provided. It isdesirable to provide two such windows in angular displacement to eachother, preferably at about 120 as near the blower l as is feasible, forthe reason that fires in duct ill invariably result from a force such asa spark set into action at blower I; and a special feature of thepresent invention is the detection of such fires in their incipientstages, which dictates that the fir detecting means should be arrangedas close as possible to the mechanism in which the fire is most likelyto be initiated, namely blower I.

Referring now to Figure 5 of the drawings, it will be observed that theduct I0 is provided with a series of windows It in substantially 120angular displacement from each other. With this arrangement of windows,ignited particles of material in duct Ill may be detected, regardless ofthe position of the same in duct i0. That is to say, no portion of theinterior of duct i0 is blinded by the walls thereof, and if an ignitedparticle should repose in a position so that it would not be detected atone window l6, it would be detected at the other window. Sucharrangement of at least two windows H5 in approximately angulardisplacement permits an adequate vista through windows of limited area,but it will be understood that equivalent results could be obtained bythe employment of a single window extending for nearly of thecircumference of the duct.

The window openings IS in the duct ID are closed by a pane of glass orother transparent material i1, and a housing is is provided thereover,suitably connected to duct In as by rivets l9. Within the housing 19 isa photo-electric cell 20, arrangedso as to receive light impulses fromthe interior of duct i0 through pane I'l. Extending from photo-electriccell 20 is a cable 2 I which is connected into the circuit now to bedescribed, it being understood that the photo-electric cells at each ofwindows iii are connected in parallel circuit relation to each other.

Referring now to Figure 2 of the drawings, the electrical circuitscontrolled by the photoelectric cells 20 will be described. As pointedout hereinbefore, the quantum of light emitted by one or a few cottonfibers, when the fire in the duct i0 is in its incipient stage, isinsufiicient to actuate an ordinary photo-electric cell to an extentsuch as to to set in motion the fire control devices of the presentinvention, and consequently the present invention especiallycontemplates that the photo-electric cell current be amplified. In orderto accomplish this, an alternating current power supply is connectedwith a transformer 22, which in turn has its secondary connected in aconventional manner, so as to supply oscillating power to thephoto-electric cells 20. In the circuit shown in the drawings, which isfor illustration only, a thermionic full wave rectifier 23 is employed.The oscillating power is impressed upon the bank of photo-electric cells20, any number of which may be provided, one for each window IS in ductl0; and the photoelectric cells are connected in parallel, so that lightdetected by any one of them will be converted into an electrical impulsesufilcient to set in motion the control devices of the presentinvention. In the circuit shown in Figure 2, three stages ofamplification are provided by a series of amplifiers 24, 25, and 26, sothat the electrical impulses resulting from the detection of a modicumof light by any one of photo-electric cells 20 is amplified, and asamplified, impressed upon a relay 21. In the embodiment shown in thedrawings, the amplifier 24 is a pentode, the amplifier 25 is a triode,and the amplifier 26 is a double triode with its elements connected inparallel. Obviously, any other arrangement of specific types ofamplifiers well known to those skilled in the art may be employed, andany desired number of amplification stages may be provided, so long asthe slight electrical impulses delivered by photo-electric cells 20 aresumciently amplified to energize and actuate relay 21.

Relay 21 is arranged to open and close a control power circuitcomprising conductors 28 and 29, being arranged as shown to make andbreak the connection through conductor 28. Connected in parallel circuitrelation across conductors 28 and 29, so as to be controlled by relay21, is a relay 30, a solenoid 3|, and a solenoid 4|.

Relay 30 is arranged, when energized, so as to break a power circuitextending from a suitable source of power through conductors 32 and 33to the motor 4, which, as hereinbefore described, operates to feedmaterial from hopper 2 to conveyor 5. Accordingly, when the system isoperating normally, relay 30 is de-energized and the circuit throughconductors 32 and 33 to motor 4 is complete; but upon detection of afire in duct l0, relay 30 becomes energized and the circuit throughconductor 32 to motor 4 is interrupted.

Solenoid 3| is arranged to actuate an armature 34 which in turn controlsfire door l2. Solenoid 4| is arranged to actuate mechanisms which inturn control the position of switch l5. When the system is operatingnormally, solenoid 3| and solenoid 4| are de-energized so that fire doorI 2 is open and switch I is in a position such as to close the mouth ofauxiliary duct l4; but upon detection of a fire, solenoids 3| and 4|become energized, so that fire door I2 is closed and switch I5 isactuated to open the mouth of auxiliary duct 4.

A convenient arrangement for operating the switch I5 is shown in Figure3. In the embodiment shown, a door 35 is fixedly mounted upon a hingepin 36, and arranged for movement between the position shown in fulllines and the position shown in broken lines. In the position shown infull lines, the door 35 completely closes the mouth of tube l4; but whenin the position shown in broken lines, the door 35 closes tube l0, andthereby diverts the stream of material through auxiliary duct l4.

In order to effect immediate actuation of door 35 upon the detection ofa fire within duct II), a crank 31 may be fixed upon pin 36 andassociated with a latch 38 pivotally mounted at 39. The latch 38 ismaintained in the position shown under normal conditions, by a dog 40connected with the solenoid 4|, connected to a suitable source ofelectric power, as described hereinbefore, and arranged to be energizedupon detection of a fire within duct Hi.

When crank 31 is in the position shown in full lines in Figure 3 (withdoor 35 closing the mouth of auxiliary duct l4) a spring 42 is undertension, so that upon release of dog 40 upon energization of solenoid4|, spring 42 is active upon crank 31 to move the latter into the brokenline position, and thereby effect diversion of the stream of materialfrom duct l0 to auxiliary duct I4.

As clearly shown in Figure 4, fire door I2 is provided with a shoulder42 beneath which a latch 43 is arranged to engage when the fire door I2is in its open position, as shown. Latch 43 is pivotally mounted upon apin 44, and maintained in horizontal position by a slide 45 connectedthrough a lever 46 with armature 34 of solenoid 3|. When the solenoid 3|is energized, the armature 34 is moved to the left as shown in Figure 4,releasing slide 45 from latch 43 and permitting the latter to rotateabout pin 44 so as to release fire door l2. The force of gravity isordinarily suflicient to move fire door l2 into the position whereat itscloses the passage through duct H], but the action of gravity may, ofcourse, be implemented by the arrangement of suitable springs.

From the foregoing description, it should be apparent that the presentinvention accomplishes kH/U! kill its object, and provides a. means ofdetecting and controlling fires in conveying systems where inflammablematerials are conducted in a stream of air or other gas. In normaloperation, the. material is mechanically fed by motor 4 from a hopper 2to conveyor 5. The material is picked up from conveyor 5 by the force ofsuction exerted by blower and is forced through duct l0, and dischargedinto picker room When, however, one or more of the photo-electric cells20 detects the presence of light within duct I0, the electrical impulsedelivered by the photoelectric cell or cells so energized is amplifiedand impressed upon relay 21, thereby completing a circuit from a sourceof power to relay 30 and solenoid 3|, energizing and actuating thelatter. Actuation of relay 30 interrupts the supply of power to motor 4,and consequently interrupts the supply of material from hopper 2 toconveyor 5. The motor 8, however, continues to operate, as it is notaffected by the action of relay 30. Simultaneously with the interruptionof power to motor 4, the mechanism controlling fire door l2 and switchI5 is actuated so as to close the former, and move the latter to aposition whereat the mouth of auxiliary duct I4 is opened. During thisstage, motor 8 having continued to operate, the fan 1 continues tooperate, with the result that the stream of inflammable materialsuspended in air continues temporarily, but is diverted from picker roomH to fire proof chamber l3. When the supply of material which was uponconveyor 5 (before the interruption of power to motor 4) has beenexhausted, no further combustible material will be fed to duct ID byblower l, but the stream of air will continue, thereby blowing out ductl0 and cleaning the same of any residual ash from the fire. Theprovision of means so arranged as to continue the fiow of air throughduct l0, after the fire has been detected, but to divert the flow to afire proof chamber, has therefore the special advantage that the duct isautomatically cleaned, and at the same time excessive pressures in theduct are avoided. After the material in duct NJ has been permitted toburn itself out, operation of blower I may be interrupted manually by asuitable switch, not shown, all the mechanism then restored to itsnormal operating position, and operation begun anew.

While the foregoing disclosure of the invention has been made withparticular reference to employment thereof in cotton mills, it is not tobe understood that the invention is to be limited to such application,or to application in the textile industry. On the contrary, the featuresof the present invention are equally adaptable to any system whereininflammable or combustible materials are transmitted in a stream of gas.It is obvious, of course, that many variations, modifications, andalterations in the speccific elements and arrangement thereof willsuggest themselves to those skilled in the art without departing fromthe spirit of this invention, and it is therefore to be distinctlyunderstood that the foregoing specific descriptions, and theillustration of specific embodiments in the drawings, are by way ofillustration and not by way of limitation. Such modifications andadaptations, and the use of such individual features and combinations offeatures as present themselves to those skilled in the art withoutdeparting from the spirit of the invention are, although notspecifically described herein, contemplated by and within the scope ofthe appended claims.

Having thus described the invention, what is claimed is:

1. The combination with a. tube for pneumatically conveying combustiblematerials, of fire control apparatus, comprising, a light sensitivedevice arranged to receive light rays emanating from burning materialwithin the tube, and means responsive to said light sensitive device fordiverting the material in the tube from its normal path toward a pointwhere it is no longer dangerous.

2. Th combination with a tube for pneumatically conveying combustiblematerials of fire control apparatus, comprising, a fire door in saidtube, a diverting tube connected with said tube ahead of said fire door,said diverting tube leading to a point where burning material is nolonger dangerous, a photoelectric cell arranged adjacent a window insaid tube ahead of said fire door and diverting tube, and meansresponsive to energization of said photo-electric cell to close saidfire door and open said diverting tube.

3. The combination with a tube for pneumatically conveying combustiblematerials, of fire control apparatus, comprising, a diverting tubeconnected with said tube, said diverting tube leading to a point whereburning material is no longer dangerous, a photo-electric cell arrangedadjacent a window in said tube ahead of said diverting tube, and meansresponsive to energization of said photo-electric cell to open saiddiverting tube.

4. In an apparatus for pneumatically conveying combustible materials, aconveying tube, means for circulating gas through said tube, means forfeeding material to the intake end of said tube, a photo-electric cellarranged to be energized by burning particles within the tube, and meansresponsive to said photo-electric cell to interrupt the feed of materialto said tube without interrupting said means for circulating gas.

5. In an apparatus for pneumatically conveying combustible materials, aconveying tube, means for circulating gas through said tube, means forfeeding material to the intake end of said tube, a fire door arranged tointerrupt the flow of materials through said tube, a photo-electric cellarranged to be energized by burning particles within the tube, and meansresponsive to said photo-electric cell to interrupt the feed of materialto said tube and close said fire door without interrupting said meansfor circulating gas.

6. In an apparatus for pneumatically conveying combustible materials, aconveying tube, means for circulating gas through said tube, saidauxiliary duct leading to a point where burning material is no longerdangerous, means for feeding material to the intake end of said tube, anauxiliary duct arranged for selective connection with said tube, aphoto-electric cell arranged to be energized by burning particles withinthe tube, and means responsive to said photoelectric cell to interruptthe feed of material to said tube and connect said auxiliary ductwithout interrupting said means for circulating gas.

7. In an apparatus for pneumatically conveying combustible materials, aconveying tube, means for circulating gas through said tube, means forfeeding material to the intake end of said tube, a fire door arranged tointerrupt the flow of materials through said tube, an auxiliary tubearranged for selective connection with said tube ahead of said firedoor, said auxiliary duct leading to a point where burning material isno longer dangerous, a photo-electric cell arranged to be energized byburning particles within the tube, and means responsive to saidphoto-electric cell to interrupt the feed of material to said tube toclose said fire door and connect said auxiliary duct withoutinterrupting said means for circulating gas.

8. In an apparatus for pneumatically conveying combustible materials, aconveying tube, means for circulating gas through said tube, means forfeeding material to the intak end of said tube, an auxiliary ductarranged for selective connection with said tube, a fire proof chamberconnected with said auxiliary duct, 8. photoelectric cell arranged to beenergized by burning particles within the tube, and means responsive tosaid photo-electric cell to interrupt the feed of material to said tubeand divert the fiow of material through said tube to said fire proofchamber without interrupting said means for circulating gas.

9. In an apparatus for pneumatically conveying combustible materials, a.substantially cylindrical conveying tube, means for circulating gasthrough said tube, means for feeding material to the intake end of saidtube, an auxiliary duct arranged for selective connection with saidtube, a fire proof chamber connected with said auxiliary duct, a seriesof light sensitive devices arranged at substantially displacement fromeach other about said tube, said light sensitive devices being connectedin parallel circuit relation with each other, a power amplifying circuitconnected in series with said bank of light sensitive devices, andcontrol means arranged to be actuated upon energization of either ofsaid light sensitive devices to interrupt the feed of material to saidtube and divert the fiow of material through said tube to said fireproof chamber without interrupting said means for circulating gas.

IRA H. McMANN.

CERTIFICATE OF CORRECTION. Patent No. 2555,6614. August 15, 19141;.

IRA H. MOMANN.

It is hereby certified that error appears in the printed specificatiozof the above numbered patent requiring correction as follows: Page 5,first column, line 70, for "its" read --it--; page 1;, firstcolumn, line59, and

second column, line 1, claim 6, strike out the words and comma "said.auxiliary duct leading to a point where burning material is no longerdangerous,"

and insert the same after "tube,", page LL, second column, line 1;; andthat the said Letters Patent should be read with this correction thereinthat the same may conform to the record of the case in the PatentOffice.

Signed and sealed this 10th day of October, A. D. 191m.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

